27/09/2002
V560 User Manual
16
4. VME INTERFACE
4.1. ADDRESSING CAPABILITY
The module works in A32/A24 mode. This means that the module address must be specified in a
field of 32 or 24 bits. The Address Modifiers code recognized by the module are:
AM=%39:
standard user data access
AM=%3D:
standard supervisor data access
AM=%09:
extended user data access
AM=%0D:
extended supervisor data access
The module's Base Address is fixed by 6 internal rotary switches housed on two piggy-back boards
plugged into the main printed circuit board (see Fig. 4.1).
The Base Address can be selected in the range:
% 00 0000 <-> % FF FF00
A24 mode
% 0000 0000 <->% FFFF FF00
A32 mode
The Base Address reserves in this way a page of 256 bytes for the module. The address map of the
page is shown in table 4.1.
4.2. DATA TRANSFER CAPABILITY
The module has the following data transfer capability:
•
the internal registers are accessible in D16 mode;
•
the counters are accessible in D16/D32 mode.
This means that the counters can be read either by Word or Long Word instructions, while the
register can be read by Word instructions only.
